SINGAPORE - Historian Thum Ping Tjin's written submission to the select committee on deliberate online falsehoods "is not an academic dissertation but a political piece", and he must expect to be questioned about the claims he put forth in it, said Mr Charles Chong.

Responding to an open letter signed by over 200 academics here and overseas defending Dr Thum, Mr Chong said on Tuesday (April 17) that it was Dr Thum who had chosen to use the committee to make a political point about Operation Coldstore - a security operation that took place 55 years ago, long before the Internet existed.

"Having done so, he cannot then plead that his claims should not be questioned, or that he should not be judged on his answers," said Mr Chong, who chairs the parliamentary committee.

He noted that Dr Thum had in his five-page written submission referred to his position as the founder of website New Naratif which Mr Chong describes as a group that is involved in political activism.

"There is nothing wrong with political activism in itself. But it is odd to make political points - as Dr Thum did - and then hide behind the shield of academia when questioned,"said Mr Chong, also the deputy speaker of Parliament.

In a two-page statement, Mr Chong set out his response to the letter which had expressed concern over how Dr Thum was questioned by committee member Law and Home Affairs Minister K. Shanmugam for six hours last month, "treating him and his widely-respected scholarship with disdain".

"This is likely to have a chilling effect on freedom of expression and academic freedom in Singapore," said the letter which began circulating online last week.

It called for Mr Chong to apologise for the committee's treatment of Dr Thum.

In his written submission to the panel, Dr Thum charged that Operation Coldstore - during which more than 100 leftist unionists and politicians were arrested - was carried out for political gain. Contrary to official statements, there was no evidence that the detainees were involved in any violent communist conspiracy to overthrow the Singapore Government, he stated.

On the contrary, then-Prime Minister Lee Kuan Yew tacitly admitted to the British Commissioner in private meetings that the purpose of Operation Coldstore was political gain, wrote Dr Thum.

The People's Action Party Government had been the main source of falsehoods in Singapore, he asserted.

Mr Chong said that Dr Thum is entitled to his views, but must be prepared to defend them.

"And indeed Dr Thum wrote that he was willing to appear before us. It is therefore surprising that the letter suggests Dr Thum was questioned 'without warning'," wrote Mr Chong.

The letter had also said that Dr Thum's research had been subject to critical peer review and said that Mr Shanmugam is not qualified to undertake a peer review of Dr Thum's research. But Mr Chong said that it is "surprising" for the letter to argue that Dr Thum's claims should not have been questioned by a parliamentary committee.

"Legislators all over the world regularly have robust exchanges with witnesses, including academics," said Mr Chong, who brought up how Facebook chief executive Mark Zuckerberg has just been questioned for two days by congressional committees in the United States. "I do not understand why special immunity is being claimed for academic historians."

It is also not clear if all the assertions that Dr Thum had made in his written submission had been peer-reviewed, said Mr Chong. He noted that Dr Thum had conceded a number of points after being questioned by the committee, including acknowledging that the British authorities had honestly believed that Operation Coldstore was necessary for security reasons and that some members of the leftist party Barisan Sosialis had considered "armed struggle" a legitimate option to pursue at some stage.

"These concessions substantially undermined his thesis that Operation Coldstore was launched purely for party political advantage," he added.

Mr Chong also said that it is not accurate to describe Dr Thum as an academic historian, and that the committee had some difficulty identifying his precise academic position.

While he had described himself as a Research Fellow in History in his submission and said in his oral testimony he was holding a visiting professorship in anthropology at Oxford University, Oxford later confirmed that he is a Visiting Fellow with the Fertility and Reproduction, and previously a Visiting Scholar at the Oxford Centre for Global History - both unpaid positions, said Mr Chong.

Mr Chong also said that the letter's concerns about academic freedom are misplaced, noting that more than 20 academics, from Singapore and elsewhere had given oral evidence to the committee.

"All were forthright in their views and I would be very surprised if any of them were intimidated by the process. To be sure, individual members of our Committee did not always agree with the academics who gave evidence to us. But we all benefited from the learning they brought to bear on the questions before us," he said.

Signatories of the letter include Professor Prasenjit Duara, former director of the Asia Research Institute of the NUS, media studies professor Cherian George of Hong Kong Baptist University and Associate Professor Lily Zubaidah Rahim of the University of Sydney,

Separately, six academics from Oxford University's Project Southeast Asia initiative also issued a statement on Monday (April 16), calling on the committee to issue a public apology for the "unacceptable treatment" of Dr Thum. Dr Thum is a coordinator and trustee with Project Southeast Asia.

The committee received a total of 170 written submissions and heard oral testimony from 65 people over eight days. It will reconvene in May to deliberate on a report of its findings to Parliament.